The present invention relates to an airbag device in which an airbag is deployed to protect an occupant in the event of vehicle collision. More particularly, the present invention relates to an airbag device which can accomplish suitable deployment of an airbag for securely and sufficiently restraining an occupant and which is improved in the smooth deployment.
It is to be noted that the present invention can be applied to any airbag devices for a driver's seat, a front passenger's seat, a rear passenger's seat, a side airbag device and so on.
Conventionally, in order to protect an occupant in the event of vehicle collision, airbag devices for a driver's seat and a front passenger's seat have been employed.
FIG. 7 is a view showing an airbag, in its fully deployed state, of a typical airbag device which has been conventionally used. The airbag device includes an airbag 51 comprising a front panel 55 and a rear panel 56, and an inflator 53 which spouts a gas into the airbag 51.
The rear panel 56 of the airbag 51 is provided with a gas inlet 52 through which a gas is spouted from the inflator 53, and vent holes 54 for discharging the gas from the inside of the airbag 51. The inflator 53 is attached to a portion around the gas inlet 52 of the rear panel 56 through a retainer (not shown).
In the conventional airbag device structured as mentioned above, the gas is spouted from the inflator 53 in the event of vehicle collision. The gas enters into the airbag 51 through the gas inlet 52 so as to deploy the airbag 51. On the other hand, a part of the gas is gradually discharged through the vent holes 54. When the head or body of an occupant collides with the airbag 51, the gas within the airbag escapes outside through the vent holes 54, so that the airbag shrinks, thereby absorbing kinetic energy of the occupant. Furthermore, after a short period of time, the airbag shrinks so as to recover a visual field for the occupant.
However, the conventional airbag device has the following problems. Namely, there is a possibility that the airbag starts to deploy even when there is an obstacle to disturb the enough deployment of the airbag. In this case, as the airbag is deployed in a state where a portion around the vent holes of the airbag is not completely deployed, an undesired load may be applied because the vent holes for gas leak are blocked.
The present invention has been made in order to solve the above problem, and an object of the present invention is to provide an airbag device which is improved in the smooth deployment.
Another object of the invention is to provide an airbag device as stated above, wherein an undesired load is not formed by the airbag.
Further objects and advantages of the invention will be apparent from the following description of the invention.